A case of short QT-interval postventricular arrhythmia arrest from Torsade De Pointes, a new phenotype, or the result of tachycardia-mediated imbalance.

INTRODUCTION: We report the case of an 18-year-old female with recurrent syncope that was discovered to have congenital long QT syndrome (LQTS) and episodes of a transiently short QT interval after spontaneous termination of polymorphic ventricular tachycardia. METHODS & RESULTS: A cardiac event monitor revealed a long QT interval and initiation of polymorphic ventricular tachycardia by a premature ventricular complex on the preceding T-wave. After 1 minute of ventricular fibrillation, her arrhythmia spontaneously terminated with evidence of a short QT interval. CONCLUSIONS: A transient, potentially artificial, short QT interval following Torsades de Pointes can occur in patients with LQTS.

Left Atrial Appendage Closure with Watchman vs Amulet Devices: Similarities and Differences.

PURPOSE OF REVIEW: Left atrial appendage closure (LAAC) has shown to be non-inferior to oral anticoagulation (OAC) for non-valvular atrial fibrillation (AF). LAAC is now becoming a leading method for stroke prophylaxis in patients who have atrial fibrillation and are unable to tolerate OAC. There are currently two FDA-approved endocardial closure devices, namely, the Watchman FLX and Amplatzer Amulet. RECENT FINDINGS: Current data highlights that both devices offer similar efficacy and safety for LAAC. While the two devices differ in terms of intraprocedural complication rates, they offer similar short- to long-term outcomes in regard to peri-device leaks, device-related thrombosis, and mortality. With similar risk and safety profiles, both devices are indicated for patients who are unable to tolerate OAC. Newer clinical studies are directed to establish the efficacy of both devices as the primary method for stroke prevention in AF as an alternate to OAC.

Stroke Risk in Atrial Fibrillation: Beyond the CHA2DS2-VASc Score.

PURPOSE OF REVIEW: Stroke prevention is the cornerstone of atrial fibrillation (AF) management and the anticoagulation decision is currently based on CHA2DS2-VASc risk score. We discuss several novel risk factors besides those included in CHA2DS2-VASc score and alternative models for stroke prediction. RECENT FINDINGS: Several clinical markers including obstructive sleep apnea and renal failure, laboratory markers like brain natriuretic peptide, imaging criteria including left atrial appendage morphology, spontaneous echo contrast, and coronary artery calcium score may predict stroke in AF patients. Addition of African American ethnicity to CHA2DS2-VASc score also improves stroke prediction in AF. Finally, novel models including TIMI-AF score, ATRIA score, and GARFIELD-AF scores have potential roles in risk stratification for stroke. While CHA2DS2-VASc score is the currently recommended risk stratification model for stroke prediction in AF, use of additional clinical, laboratory, imaging markers, ethnicity, and novel stroke prediction models may further assist in decision to anticoagulate the AF patient for stroke prevention.

Perioperative predictors of permanent pacing and long-term dependence following tricuspid valve surgery: a multicentre analysis.

AIMS: Permanent pacemaker placement (PPM) is often required after valvular surgery and is especially common following tricuspid valve surgery [tricuspid valve repair or replacement (TVR)]. Literature suggests that surgical intervention for isolated tricuspid valve disease is becoming more prevalent. Predictors of PPM dependency following TVR are currently unknown and would be clinically useful from a prognostication standpoint. METHODS AND RESULTS: We conducted a multicentre, retrospective study to assess perioperative factors of TVR that predispose to PPM placement and long-term PPM dependency from 2008 to 2014. Regression analysis was used to determine independent predictors of PPM implantation. A total of 237 patients (age 66 ± 15 years, 29% male) were studied, and the incidence of PPM placement following TVR was 27% (65/237). No significant differences were observed between those who received PPM and those who did not in age (P = 0.092), gender (P = 0.359), and co-morbidities. Regression analysis identified cross-clamp time >60 min (OR 4.1, 95% CI 1.3-12.9, P = 0.015) and concomitant mitral valve surgery (OR 3.8, 95% CI 1.2-12.2, P = 0.026) as independent risk factors for PPM following TVR. Long-term PPM dependency data were only available in 28 patients who received PPM with 14 of these patients developing long-term dependence. The only statistically significant difference noted was an increased frequency of coronary artery disease in the long-term dependent group vs. the non-dependent group (64% vs. 14%, P = 0.018). CONCLUSION: Cross-clamp time >60 min and concomitant mitral valve surgery were independent predictors of PPM implantation following TVR. Long-term PPM dependency is more prevalent after TVR than other types of valvular surgery.

Frailty and associated outcomes in patients undergoing percutaneous left atrial appendage occlusion: findings from the NCDR LAAO registry.

BACKGROUND: Frailty is associated with significant morbidity and mortality and may have clinical implications in an advanced age population with atrial fibrillation undergoing left atrial appendage occlusion (LAAO). We sought to develop a novel frailty scale to predict worse outcomes in patients undergoing LAAO. METHODS: Patients in the NCDR LAAO Registry between 2016 and 2021 receiving percutaneous LAAO devices were categorized as non-frail (0 points), pre-frail (1-3 points), or frail (4-5 points) based on a 5-point scale representing multiple domains of frailty: hemoglobin <13.0 g/dL in male, <12.0 g/dL in female; creatinine ≥1.2 mg/dL; albumin <3.5 g/dL; body mass index <20 kg/m2; and increased risk of falls. RESULTS: Of 57,728 patients, 44,360 (76.8%) were pre-frail and 7693 (13.3%) were frail. Compared to non-frail, pre-frail and frail patients were older, had a higher burden of co-morbidities, and more disability based on the Modified Rankin Scale. Compared to non-frail patients after adjustment, frail patients were at higher risk of in-hospital major complication (OR 1.29, 95% 1.02-1.62, p = 0.01), any complication (OR 1.29, 95% CI 1.09-1.52, p = 0.0005), and death (OR 5.79, 95% CI 1.75-19.17, p = 0.001), while no difference was observed in pre-frail patients. At 45-day follow-up, there was no difference in the risk of complications in frail patients as compared to non-frail, although mortality was significantly higher (OR 3.01, 95% CI 1.97-4.85, p < 0.0001). CONCLUSION: A simple and practical frailty scale accurately predicts adverse events in patients undergoing LAAO. The 13% of patients considered frail were at significantly higher risk of in-hospital adverse events and 45-day mortality.

Bilateral Cardiac Sympathetic Denervation for Refractory Multifocal Premature Ventricular Contractions in Patients With Nonischemic Cardiomyopathy.

BACKGROUND: Bilateral cardiac sympathetic denervation (BCSD) for refractory life-threatening ventricular arrhythmias is a neuromodulatory intervention targeting sympathetically driven focal or re-entrant ventricular arrhythmias. OBJECTIVES: This study sought to provide a more complete and successful option for intervention in patients in whom premature ventricular contraction (PVC) ablation is not feasible or has been unsuccessful. METHODS: A total of 43 patients with >5% PVC burden and concomitant nonischemic cardiomyopathy (NICM) who previously failed medical and ablation therapies were referred for BCSD. All patients underwent bilateral video-assisted thoracoscopic surgical approach with T1-T4 sympathectomy. Primary effectiveness endpoints were postprocedural PVC burden resolution, improvement in left ventricular ejection fraction (LVEF), and cessation of antiarrhythmic drugs (AADs). Safety endpoints included peri- and postprocedural complications. Outcomes were assessed over a 1-year follow-up period. RESULTS: Among the 43 patients who underwent BCSD, the mean age was 52.3 ± 14.7 years, 69.8% of whom were male patients. Presenting mean LVEF was 38.7% ± 7.8%, and PVC burden was 23.7% ± 9.9%. There were significant reductions in PVC burden postprocedurally (1.3% ± 1.1% post-BCSD, compared with 23.7% ± 9.9% pre-BCSD, P < 0.001) and improvements in LVEF (46.3% ± 9.5% post-BCSD, compared with 38.7% ± 7.8% pre-BCSD, P < 0.001). The rate of ICD therapies decreased from 81.4% (n = 35) to 11.6% (n = 5) (P < 0.001), leading to a significant reduction in use of AADs (100.0% to 11.6%, P < 0.001) and improvement in mean NYHA functional class (2.5 ± 0.5 to 1.4 ± 0.2, P < 0.001). Major intraoperative complications were seen in 4.7% of patients (hemothorax and chylothorax). Of the patients, 81.4% (n = 35) experienced no mortality or major complications over a 1-year follow-up period, with the remaining still within their first year postprocedure. CONCLUSIONS: BCSD is effective for the management of refractory PVCs and ventricular tachycardia who have failed previous ablation therapy.

Impact of an Organized Treatment Pathway on Management of Atrial Fibrillation: The ER2EP Study.

Background: Atrial fibrillation (AF) is the most common arrhythmia reported worldwide. There is significant heterogeneity in AF care pathways for a patient seen in the emergency room, impacting access to guideline-driven therapies. Objectives: The purpose of this study was to compare the difference in AF outcomes between those treated with an organized treatment pathway vs routine-care approach. Methods: The emergency room to electrophysiology service study (ER2EP) is a multicenter, prospective observational registry (NCT04476524) enrolling patients with AF from sites where a pathway for management of AF was put in place compared to sites where a pathway was not in place within the same health system and the same physicians providing services at all sites. Multivariable regression modeling was performed to identify predictors of clinical outcomes. Beta coefficient or odds ratio was reported as appropriate. Results: A total of 500 patients (ER2EP group, n = 250; control group, n = 250) were included in the study. The mean age was 73.4 ± 12.9 years, and 52.2% were males. There was a statistically significant difference in primary endpoint [time to ablation (56 ± 50.9 days vs 183.3 ± 109.5 days; P < 0.001), time to anticoagulation initiation (2.1 ± 1.6 days vs 19.7 ± 35 days, P < 0.001), antiarrhythmic drug initiation (4.8 ± 7.1 days vs 24.7 ± 44.4 days, P < 0.001) compared to the control group, respectively. As such, this resulted in reduced length of stay in the ER2EP group compared to the control group (2.4 ± 1.4 days vs 3.23 ± 2.5 days, P = 0.002). Conclusions: This study provides evidence that having an organized pathway from the emergency department for AF patients involving electrophysiology services can improve early access to definitive therapies and clinical outcomes.

Lower-adherence direct oral anticoagulant use is associated with increased risk of thromboembolic events than warfarin.

BACKGROUND: Real-world data have suggested inconsistent adherence to oral anticoagulation for thromboembolic event (TE) prevention in patients with Non valvular atrial fibrillation (NVAF), yet it remains unclear if event risk is elevated during gaps of non-adherence. OBJECTIVE: To compare difference in outcomes between direct oral anticoagulant (DOAC) and warfarin based on adherence to the therapy in patients with NVAF. METHODS: Using the MarketScan claims data, patients receiving prescription of warfarin or a DOAC for NVAF from January 2015 to June 2016 were included. Outcomes included hospitalization for TE (ischemic stroke or systemic embolism), hemorrhagic stroke, stroke of any kind, and major bleeding. Event rates were reported for warfarin and DOACs at a higher-adherence proportion of days covered (PDC > 80%) and lower-adherence (PDC 40-80%). RESULTS: The cohort included 83,168 patients prescribed warfarin (51% [n = 42,639]) or DOAC (49% [n = 40,529]). Lower adherence occurred in 36% (n = 15,330) of patients prescribed warfarin and 26% (n = 10,956) prescribed DOAC. As compared to higher-adherence warfarin after multivariable adjustment, the risk of TE was highest in lower-adherence DOAC (HR 1.26; 95% CI, 1.14-1.33), and lowest in higher-adherence DOAC (HR, 0.93; 95% CI, 0.88-0.99). There was a significantly higher risk of hemorrhagic stroke and stroke of any kind in the lower-adherence groups. Major bleeding was more common with lower-adherence DOAC (HR, 1.43, 95% CI, 1.35-1.52) and lower-adherence warfarin (HR, 1.32, 95% CI, 1.26-1.39). CONCLUSIONS: In this large real-world study, low adherence DOAC was associated with higher risk of TE events as compared to high and low adherence warfarin.

Feasibility and safety of a novel blunt tip concealed needle device for pericardial access in porcine models.

BACKGROUND: Percutaneous pericardial access is the cornerstone of various procedures in clinical cardiology. The two commonly used methods utilizing large bore (LB) and smaller micropuncture (MP) needles often lead to inadvertent RV punctures. As both of these techniques push the pericardium inward, the novel blunt tip concealed needle device (BTCND) introduces the concept of bringing a small portion of the pericardium into a tube, where needle puncture and guidewire can be passed into the pericardial space all within the safety of the tube. METHODS: The BTCND (Via One®, CardioVia, Nazareth, Israel) is a tool designed to allow for safe percutaneous subxiphoid pericardial access. In this preclinical study, a total of 18 procedures were performed in 5 female pigs. All procedures were performed under general anesthesia and under fluoroscopic guidance with a team of veterinarians and cardiac electrophysiologists. A laparoscopic camera was used to demonstrate and record the procedure. The Institutional Animal Care and Use Committees approved all preclinical experiments. RESULTS: A total of 18 procedures were performed on five female pigs. In all procedures, the physicians safely introduced guidewire into the pericardial space. Device operation was not associated with any adverse events or bleeding, nor was any damage seen to the pericardium, the heart, or other organs during the procedure. CONCLUSION: The result of our preclinical report demonstrates that the device is intuitive, easy to use, and effective for its intended use. Large preclinical studies are needed to validate the results of the study.

Data deluge from remote monitoring of cardiac implantable electronic devices and importance of clinical stratification.

Background: Remote monitoring (RM) has been accepted as a standard of care for follow-up of patients with cardiac implantable electronic devices (CIEDs). However, the resulting data deluge poses major challenge to device clinics. Objective: This study aimed to quantify the data deluge from CIED and stratify these data based on clinical relevance. Methods: The study included patients from 67 device clinics across the United States being remotely monitored by Octagos Health. The CIEDs included implantable loop recorders, pacemakers, implantable cardioverter-defibrillators, cardiac resynchronization therapy defibrillators, and cardiac resynchronization therapy pacemakers. Transmissions were either dismissed before reaching the clinical practice if they were repetitive or redundant or were forwarded if they were either clinically relevant or actionable transmission (alert). The alerts were further classified as level 1, 2, or 3 based on clinical urgency. Results: A total of 32,721 patients with CIEDs were included. There were 14,465 (44.2%) patients with pacemakers, 8381 (25.6%) with implantable loop recorders, 5351 (16.4%) with implantable cardioverter-defibrillators, 3531 (10.8%) with cardiac resynchronization therapy defibrillators, and 993 (3%) with cardiac resynchronization therapy pacemakers. Over a period of 2 years of RM, 384,796 transmissions were received. Of these, 220,049 (57%) transmissions were dismissed, as they were either redundant or repetitive. Only 164,747 (43%) transmissions were transmitted to the clinicians, of which only 13% (n = 50,440) had clinical alerts, while 30.6% (n = 114,307) were routine transmissions. Conclusion: Our study shows that data deluge from RM of CIEDs can be streamlined by utilization of appropriate screening strategies that will enhance efficiency of device clinics and provide better patient care.

Poorer outcomes associated with more invasive lead management strategies for Abbott Riata® leads: a large, multicenter experience.

BACKGROUND: Over 100,000 Abbott Riata® were implanted in the United States before they were recalled in 2010. There are still a significant number of Abbott Riata® leads in use, and it is unclear how these leads should be managed at the time of generator change or lead malfunction. Although data comparing both Sprint Fidelis® and Abbott Riata® leads in this setting is available, there are no multicenter comparative studies of outcomes for various lead management strategies, including lead extraction (LE), lead abandonment/revision (LA), and generator change (GC) only at the time of device at elective replacement interval (ERI) for Abbott Riata® leads. METHODS: A retrospective, multicenter study was undertaken to compare short-term outcomes (major complications-MC, death, extended or re-hospitalizations within 60 days-RH, lead malfunction-LM) and total outcomes (short-term outcomes & lead malfunction during follow-up) of patients with Riata® leads undergoing LE, LA, or GC. RESULTS: 152 patients (65 ± 13 years, 68% male) were followed for a mean 33 ± 30 months following intervention. Out of 166 procedures, 13 patients underwent LE, 16 patients underwent LA, and 137 patients underwent GC. There was 1 major complication in each group, yielding an event rate of 7.7% for LE, 6.3% for LA, and 0.7% for GC cohorts. There were significantly more short-term and total adverse outcomes in the group of patients getting LE and LA versus GC only (38.5% & 31.3% vs 7.3%, P < 0.001). Total Riata® lead dwell time follow-up was 17,067 months. A total of 3 Riata® lead malfunctions were noted during long-term follow-up. Inappropriate shocks were similar between LE 7.7% (1/13), LA 6.3% (1/16). and GC 11.0% (4/136); P = 0.57. CONCLUSIONS: There were more short-term and total adverse outcomes in more invasive management strategies (LE and LA) versus GC alone. The failure rate of Riata® leads was substantially lower compared to previous reports. Therefore, we recommend only performing battery exchange when a device with an active Riata® lead is at ERI, unless there is malfunction of the Riata® lead noted on testing. There were significantly more short-term adverse outcomes in the lead extraction (5/13) and lead abandonment/revision (5/16) groups than the generator only (8/137) group (P < 0.001). GIB - Gastrointestinal bleed, CHF - congestive heart failure, NSTEMI - non-ST elevation MI.

Multidisciplinary Critical Care Management of Electrical Storm: JACC State-of-the-Art Review.

Electrical storm (ES) reflects life-threatening cardiac electrical instability with 3 or more ventricular arrhythmia episodes within 24 hours. Identification of underlying arrhythmogenic cardiac substrate and reversible triggers is essential, as is interrogation and programming of an implantable cardioverter-defibrillator, if present. Medical management includes antiarrhythmic drugs, beta-adrenergic blockade, sedation, and hemodynamic support. The initial intensity of these interventions should be matched to the severity of ES using a stepped-care algorithm involving escalating treatments for higher-risk presentations or recurrent ventricular arrhythmias. Many patients with ES are considered for catheter ablation, which may require the use of temporary mechanical circulatory support. Outcomes after ES are poor, including frequent ES recurrences and deaths caused by progressive heart failure and other cardiac causes. A multidisciplinary collaborative approach to the management of ES is crucial, and evaluation for heart transplantation or palliative care is often appropriate, even for patients who survive the initial episode.

Long-Term Imaging and Clinical Outcomes of Surgical Left Atrial Appendage Occlusion With AtriClip.

Surgical left atrial appendage (LAA) occlusion with an AtriClip (AtriCure, West Chester, Ohio) is frequently performed for stroke prophylaxis in patients with atrial fibrillation (AF). We conducted a retrospective analysis of all patients with long-standing persistent AF who underwent hybrid convergent ablation and LAA clipping. Contrast-enhanced cardiac computed tomography was performed at 3 to 6 months after LAA clipping to assess the degree of complete closure and the residual LAA stump. A total of 78 patients (64 ± 10 years, 72% male) underwent LAA clipping as part of hybrid convergent AF ablation, from 2019 to 2020. Median size of AtriClip used was 45 mm. Mean LA size was 4.6 ± 1 cm. At 3-to-6 months follow-up computed tomography, 46.2% of patients (n = 36) had a residual stump proximal to the deployed LAA clip. Mean depth of residual stump was 3.95 ± 5.5 mm, with 19% of patients (n = 15) having a stump depth of ≥10 mm and 1 patient requiring more endocardial LAA closure owing to large stump depth. During 1-year follow-up, 3 patients developed stroke; device leak of 6 mm was noted in 1 patient; and none of the patients had a thrombus proximal to the clip. In conclusion, high incidence of residual LAA stump was observed with AtriClip. Larger studies with long-term follow-up are needed to better assess the thromboembolic implications of a residual stump after AtriClip placement.

Impact of Remote Cardiac Monitoring on Greenhouse Gas Emissions: Global Cardiovascular Carbon Footprint Project.

Background: Remote monitoring (RM) of patients with cardiac implantable electronic devices (CIEDs) is efficient and requires fewer resources than conventional monitoring. However, the impact of RM on the carbon footprint (CF) is not known. Objectives: The authors sought to evaluate the reduction in cost and greenhouse gas (GHG) emissions with RM as compared to conventional monitoring of CIEDs and its relevance to CF. Methods: Data were obtained from a third-party RM provider on 32,811 patients from 67 device clinics across the United States. Distance from home address to the device clinic for patients on RM was calculated. Savings in total distance traveled over 2 years was calculated using frequency of follow-up required for the device type. National fuel efficiency data and carbon emission data were obtained from the Bureau of Transportation Statistics and U.S. Environmental Protective Agency, respectively. The average gas price during the study period was obtained from U.S. Energy Information Administration. Results: In the study population, RM resulted in a total saving of 31.7 million travel miles at $3.45 million and reduction of 12,518 metric ton of GHG from gasoline. There was a reduction of 14.2-million-page printouts, $3 million in cost, and 78 tons of GHG. Improvement in workforce efficiency with RM resulted in savings of $3.7 million. There was a net saving of $10.15 million and 12,596 tons of GHG emissions. Conclusions: RM of patients with a CIED resulted in significant reductions in GHG emissions. Efforts to actively promoting RM can result in significant reduction in CF.

Risk of Arrhythmic Death in Patients With Nonischemic Cardiomyopathy: JACC Review Topic of the Week.

Nonischemic cardiomyopathy (NICM) is common and patients are at significant risk for early mortality secondary to ventricular arrhythmias. Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy to decrease sudden cardiac death (SCD) in patients with heart failure and reduced left ventricular ejection fraction. However, in randomized clinical trials comprised solely of patients with NICM, primary prevention ICDs did not confer significant mortality benefit. Moreover, left ventricular ejection fraction has limited sensitivity and specificity for predicting SCD. Therefore, precise risk stratification algorithms are needed to define those at the highest risk of SCD. This review examines mechanisms of sudden arrhythmic death in patients with NICM, discusses the role of ICD therapy and treatment of heart failure for prevention of SCD in patients with NICM, examines the role of cardiac magnetic resonance imaging and computational modeling for SCD risk stratification, and proposes new strategies to guide future clinical trials on SCD risk assessment in patients with NICM.

Feasibility and Safety of Intravenous Sotalol Loading in Adult Patients With Atrial Fibrillation (DASH-AF).

BACKGROUND: Inpatient initiation of sotalol is recommended owing to its proarrhythmic effects. OBJECTIVES: The DASH-AF (Feasibility and Safety of Intravenous Sotalol Administered as a Loading Dose to Initiate Oral Sotalol Therapy in Adult Patients With Atrial Fibrillation) trial evaluates the safety and feasibility of intravenous (IV) sotalol, achieving a steady state with maximum QTc prolongation within 6 hours instead of the traditional 5-dose inpatient oral (PO) titration. METHODS: DASH-AF is a prospective, nonrandomized, multicenter, open-label trial consisting of patients who underwent IV sotalol loading dose to initiate rapid oral therapy for atrial arrhythmias. IV dose was calculated based on the target oral dose as indicated by baseline QTc and renal function. Patients' QTc (in sinus) was measured via electrocardiography at 15-minute intervals and after IV loading completion. Patients were discharged 4 hours after first oral dose. All patients were monitored via mobile cardiac outpatient telemetry for 72 hours. The control group was composed of patients admitted for the traditional 5 PO doses. Safety outcomes were assessed in both groups. RESULTS: A total of 120 patients from 3 centers were enrolled from 2021 to 2022 in the IV loading group (compared with type of AF- and renal function-matched patients in the conventional PO loading cohort). This study demonstrated no significant change in ΔQTc in both groups, with a significantly lower number of patients requiring dose adjustment in the IV arm compared with the PO arm (4.1% vs 16.6%; P = 0.003). This led to potential cost savings of up to $3,500.68 per admission. CONCLUSIONS: The DASH-AF trial shows that rapid IV sotalol loading in atrial fibrillation/flutter patients for rhythm control is feasible and safe compared with conventional oral loading with significant cost reduction. (Feasibility and Safety of Intravenous Sotalol Administered as a Loading Dose to Initiate Oral Sotalol Therapy in Adult Patients With Atrial Fibrillation [DASH-AF]; NCT04473807).

Catheter ablation targeting complex fractionated atrial electrograms for the control of atrial fibrillation.

PURPOSE OF REVIEW: Catheter ablation of persistent atrial fibrillation has a lower success rate than for paroxysmal atrial fibrillation, due to structural, electrical and anatomical remodeling of the left atrium. Ablation strategies targeting complex fractionated atrial electrograms (CFAEs) are commonly employed to identify and eliminate the substrate responsible for atrial fibrillation maintenance in persistent cases. This review discusses the pathophysiology as well as the role of targeting CFAEs in catheter ablation of atrial fibrillation. RECENT FINDINGS: As our understanding regarding the origin and role of CFAEs in atrial fibrillation continues to evolve, there have been multiple recent studies looking at pathophysiology, distribution and significance of CFAEs in atrial fibrillation. In addition, different ablation strategies targeting CFAEs have been compared with the standard pulmonary vein isolation in persistent as well as paroxysmal atrial fibrillation. Recent meta-analysis studies have striven to identify atrial fibrillation patients who would benefit from CFAE ablation. SUMMARY: Whereas CFAE ablation in addition to standard pulmonary vein isolation improves outcomes in patients with persistent atrial fibrillation, there is no benefit of CFAE ablation in paroxysmal atrial fibrillation. Further studies are required to define and identify CFAEs more accurately, in a standardized manner, to enhance the success of catheter ablation and freedom from atrial fibrillation.

Beyond Ejection Fraction: Novel Clinical Approaches Towards Sudden Cardiac Death Risk Stratification in Patients with Dilated Cardiomyopathy.

Implantable Cardioverter-Defibrillator (ICD) therapy is indicated for patients at risk for sudden cardiac death due to ventricular tachyarrhythmia. The most commonly used risk stratification algorithms use Left Ventricular Ejection Fraction (LVEF) to determine which patients qualify for ICD therapy, even though LVEF is a better marker of total mortality than ventricular tachyarrhythmias mortality. This review evaluates imaging tools and novel biomarkers proposed for better risk stratifying arrhythmic substrate, thereby identifying optimal ICD therapy candidates.

Emerging role of artificial intelligence in cardiac electrophysiology.

Artificial intelligence (AI) and machine learning (ML) have significantly impacted the field of cardiovascular medicine, especially cardiac electrophysiology (EP), on multiple fronts. The goal of this review is to familiarize readers with the field of AI and ML and their emerging role in EP. The current review is divided into 3 sections. In the first section, we discuss the definitions and basics of AI, ML, and big data. In the second section, we discuss their application to EP in the context of detection, prediction, and management of arrhythmias. Finally, we discuss the regulatory issues, challenges, and future directions of AI in EP.